[imp] magick quotes in spam reporting setup

[Chuck Hagenbuch]

Quoting Dmitriy MiksIr <miksir at maker.ru>:

> As i use per-user spamassassin settings, i want learn spam on user's 
> report for this user only. For this i use
> /usr/bin/spamc -L spam -u '%u'
> or
> /usr/bin/spamc -L ham -u '%u'
> construction, but it's need a little patch.
> May be it will be usefully for other ppl's...

Looks reasonable to me. Committed, it will be in IMP 4.1. Thanks!

-chuck

-- 
"But she goes not abroad in search of monsters to destroy." - John 
Quincy Adams